The author forgot to mention mouse gestures. The reason I still use Opera over Chrome is because of its excellent support for mouse gestures (the various mouse gesture extensions just aren't that responsive and smooth as Opera's native ones are). To switch tabs I just hold the right mouse button and turn the scroll wheel. To open up a new tab I hold the right mouse button and move the mouse a few pixels down, it doesn't even have to be that precise. For moving back and forward in browser history, I do right button + left mouse button and left mouse button + right mouse button respectively. I wish OS's had native support for mouse gestures system-wide, I think they're widely under-utilized.